Field of the Invention
The present invention relates to a technique for transporting a processing liquid to be supplied to a process object.
Description of Related Art
Semiconductor manufacturing processes include a photolithography process that applies a resist in a form of a film onto a semiconductor wafer (hereinafter referred to as “wafer”) as a process object, and exposes the resist film with a predetermined pattern, and develops the resist film to form a resist pattern.
Various processing liquids, such as a resist liquid for forming a resist film and a developer, are used in the photolithography process. For example, as described in JP2008-006325A (see Paragraphs 0044 and 0048 and FIG. 4). These processing liquids are stored in individual containers (processing liquid sources). The interior of the container is pressurized with a gas to push out the processing liquid therefrom to transport the processing liquid toward a nozzle (discharging part) for supplying the processing liquid to a wafer.
In a case where a pressurized gas is used for driving a processing liquid, the gas is dissolved in the processing liquid and might be released from the processing liquid to generate bubbles in the processing liquid due to pressure fluctuation during transportation of the liquid. The supply of such a processing liquid containing bubbles results in non-uniform coating and/or generation of defects in a film.